Cardinal Tetra for Dinner

[zoe]

I have read in several places on the Web that Cardinal Tetra are a compatible tank mate for Discus. And I have had 5 in my tank as "dither fish" for a couple months. But last night I added three more, one of which was the largest of all of them.

I added them into the tank after they'd spent a week in quarantine. They all seemed healthy. Also, I had just fed the Discus a good helping of live black worms. But, immediately upon the largest tetra being added, it immediately began being seen as a food interest of two or three of my eight 3-4" Discus (75 gal tank). Within minutes the tetra was dead from being chased down and attacked. By the time I got my longer net, nearly all the Discus were gathering around it taking pecks.

This morning I notice I am down to 6. One vanished in the middle of the night!

What's going on here? Any ideas?

[Wahter]

I have read in several places on the Web that Cardinal Tetra are a compatible tank mate for Discus. And I have had 5 in my tank as "dither fish" for a couple months. But last night I added three more, one of which was the largest of all of them.

I added them into the tank after they'd spent a week in quarantine. They all seemed healthy. Also, I had just fed the Discus a good helping of live black worms. But, immediately upon the largest tetra being added, it immediately began being seen as a food interest of two or three of my eight 3-4" Discus (75 gal tank). Within minutes the tetra was dead from being chased down and attacked. By the time I got my longer net, nearly all the Discus were gathering around it taking pecks.

This morning I notice I am down to 6. One vanished in the middle of the night!

What's going on here? Any ideas?

Your title "Cardinal Tetra for Dinner" answered your own question.


Walter

[Jhhnn]

I suspect that your long-time tetra residents have learned how to not act like food, whereas the new guy never had a chance to figure it out... Quite how that's accomplished, I have no idea, but it's really the only thing that makes sense.

Maybe it's like acting scared in a bad neighborhood, or trying to run from a mean dog...

I'm not sure how long the rest will make it, now that the discus recognize cardinals as interesting and lively snacks...

[nesser]

I have 15 cardinal tetras in with 6 adult discus in a 90 gallon.The tetras keep to there school for a good reason they have alot of planted area to keep safe.If they tried to occupie the Discus turf they would be sorry.lol

[alpine]

I had the same happen in my wife's tak with Large Angel Fish !

[Scribbles]

If it can fit in the discus' mouth it's a potential snack. Sometimes smaller fish work out and sometimes they don't. Just like dogs and cats. One of my dogs likes my cat the other one would like the cat for lunch. You never know how predatory an animal will be.

Chris

[rbarn]

If it can fit in the discus' mouth it's a potential snack. Sometimes smaller fish work out and sometimes they don't. Just like dogs and cats. One of my dogs likes my cat the other one would like the cat for lunch. You never know how predatory an animal will be.

Chris


Yep, always read good rule of thumb with any fish is

If its less than twice the size of the bigger fish's mouth
then it has a chance of being Dinner.

[Mr Wild]

Yep I gave up everything I put in my tank ended up being a snack sooner or later even small bristlenoses! So I have large discus and 2 large BN and I leave it at that in the display tank.

[poconogal]

Like others said, you never know... When I started my current tank, I had my Cardinals in there for 2 months before I bought any Discus. The Cards were well established and when the Discus went in, I had no problems. Now I have one old one left who will swim right in the middle of them for food at feeding time. The Discus could care less. The other's died of old age. The funny thing is that when I had the full school of Cards and I added 3 Panda corys who were pretty small, the Cards were attacking them! But again, my Discus could care less!

Something that can help when adding any new fish after QT is to add them at night, with the tank lights out or shutting off the lights as soon as the new fish is added.

[captain morgan]

Having just a few dither fish will look like an easy meal to your other fish in the tank, you want to have at least 15-20 cardinals to school together and be like a gang, strength in numbers so to speak, your other fish must know they are here to stay and not just a snack passing through!

[Darrell Ward]

My 240 gal. is filled with full grown adult discus. I started out with 50 cardinals about a year and a half ago. It's impossible to count them in there, but I know that at least 15 to 20 have went missing in that time. Adult discus will take a few over time, although I've never seen a discus attack them, I know it happens occasionally, because I've never found a body.

[Armandi_Fishcarer]

These things happen in the hobby, as they would in their own environmental habitat. A fish when hungry will try & feast on anything. I find that if there are plenty of hiding places, such as bunched plants & a large enough tank area, certain species will keep to there own. When introducing new smaller fish stock into an aqurium with larger fish, it is best done when lights go out or just after a feeding. You can even do a partial w/c as this will make the existing fish take a step back.

Regards
Ahmed ;)

[BAM]

I have had varying success when moving cardinal tetras. Sometimes I will but a dozen and all will be fine, and sometimes I loose a couple during transport home (20 minutes). If I buy the exact number I want, I loose a few, and if I buy a few extras I don't loose any. When I get them home and put them in a tank, or move them from quarentine to the show tank, sometimes the stress seems to disorient them somewhat, making them more of an easy target than after they settle in. If a new school of cardinals make it through a week, they generally live 2 years or more for me. I might suggest a tank divider to separate the cardinals from the discus for the first few days.

BAM

[KDodds]

I recently did a 48 hour blackout on my 135 planted only to find that half the school of Cardinals was decimated (and my Alenquer has an external eye infection). Weird how changing light can alter things so much, back to the normal photoperiod and the discus aren't chasing cardinals around and the BD isn't beating the tar out of the Alenquer any more.

[discolove]

My cardinal tetras do fine with my discus, its the glowlight tetras that end up missing after awhile. I had 6 of them to begin with and then 4 went missing so I restocked another 10 in there and I know theres less then 10 as of now.

[dvc_r]

My 240 gal.
just wondering if your married?

[plaza80]

Well I got cardinal and discus so I cross my fingers because cardinals aren't cheap either. That is a classic combination IMO.